Mica splitting machine



c. GOODMAN 2,471,738 MICA SPLITTING MACHINE May 31, 1949.

Filed March 16, 1946 2 Sheets-Sheet l INVENTOR. i B I C/Qn? 40004214? I l 1. Guam /MML C. GOQDMAN MIGA SPLITTING MACHINE May 31, 1949.

2 sheets-sheet 2 Filed March 16, 1946 IN V EN TOR. 670/1? @oq ma'n Patented May 31, 1949 MICA SPLITTING MACHINE Clark Goodman, Cambridge, Mass., assignor to New England Mica Company, Waltham, Mass., a corporation of Massachusetts Application March 16, 1946, Serial No. 654,962

Claims.

This invention relates to a mica splitting machine.

The object of the invention is to provide a novel and improved construction of mica splitting machine which is designed to operate upon the mica blocks or pieces of mica in the condition in which they are mined. in order to separate mica flakes or laminae therefrom to the end that such flakes may be utilized in the manufacture of mica insulation and other laminated mica plates and sheets.

With this general object in view, and such others as may hereinafter appear, the invention consists in the mica splitting machine and in the various structures, arrangements and combinations of parts hereinafter described and particularly defined in the claims at the end of this specification. i

In the drawings illustrating the preferred form of the invention, Fig. l is a plan view, partly in cross section, of a mica splitting machine embodying the present invention; and Fig. 2 is a transverse sectional view of the machine taken on the line 2-2 of Fig. 1.

The mica blocks or pieces of mica in the condition in which they are available commercially for the production therefrom of extremely thin mica flakes or laminae, vary in size and it is desirable that a mica splitting machine be provided which functions not only to split the mica rapidly but in such manner as to produce extremely thin mica flakes or laminae of as large a size as is possible. In other words, it is desirable that the machine function without comminuting the mica flakes, and without substantially reducing the area thereof. Accordingly, the present mica splitting machine comprises in general a pair of suetion rolls arranged to be driven and between which the mica to be split is passed. Provision is made for controlling the effect or operation of the suction exerted upon the outer laminae of the piece of mica which at the moment is being passed through the bight of the rolls to a short portion of the total circumference of the cylindrical rolls. In practice arcs of from 30 to 40 have been found most satisfactory for this pur' pose and provision is made for confining the effect of the suction to just before the bight of the rolls is reached and for a short distance thereafter. In this manner the outer laminae of the block of mica are caused by the suction to follow the contour of the rolls with the result that extremely thin outer laminae are separated from the intermediate portion of the block of mica, and provision is made for collecting the intermediate and thicker residual portion of the mica block after it has passed through the cooperating suction rollers to the end that such intermediate portion may be subjected to further splitting, as will be described,

Referring now to the drawings, the improved mica splitting machine is provided With twodriven perforated rollers or cylinders, indicated generally at l8, l2, preferably mounted in suitable bearings to be rotated from a motor I6 through gearing 48. The rollers It, it are preferably closely spaced from one another so that when a block or piece of mica indicated at 2|] is introduced into the bight of the rollers the outer laminations on opposite sides of the blocks are drawn into contact with the surface of the cylinders, and are held in such position by the effect of the suction as the laminations draw away from one another in passing from the bight of the rolls, thus, in most instances, separating the block: of mica into three separate pieces, the two thin outer lamina-e or flakes 22 and thethicker and heavier central or intermediate portion 24.

The mica splitting machine is also preferably provided with a knife 26 operatively supported and adjustably mounted on the machine frame in a position to engage the end of the block 29 as it is passing from the bight of the rolls and the presence of the knife serves to prevent the flapping of the entire and somewhat flexible piece of mica, as it emerges from the bight of the rolls, to one side or the other and thus preventing complete detachment of one of the outer laminations from its roll. The knif extending up as it does to near the bight of the rolls, not only facilitates the splitting operation under the forces set up by the suction but also in engaging the end of the mica piece deflects the movable piece slightly so that it enters between one of the outer laminae and the remainder. Then as the outward movement from the bight of the rolls continues, the thicker and unsplit piece is deflected by the knife and held so that the outer surface is against the corresponding cylinder thus eifecting further splitting off of a second thin lamination.

As a result of experimental research, it has been found that in order to effect the above described splitting of the mica pieces and the production of two thin laminae as the result of a mica block passing between the cylinderor rolls, it is preferred to maintain within the rolls l8, I2 an amount of vacuum corresponding to 20 of water. In order to maintain such a vacuum in the cylinders, I have provided means within each cylinder for confining the effect of the suction upon the mica block passing between the cylinders to the immediate vicinity of the bight of the rolls. For this purpose, each rotating perforated cylinder l0, I2 is provided with an adjustable valve comprising stationary sleeves 54, 56 mountedtobe c-apableof adjustment with relation to each other and to thdouter cylinder to vary the'elfective suction area adjacent the bight of the rolls to provide the most efficient setting for performing the splitting operation.

In the illustrated embodiment of the apparatus, each roller indicated generally at I and i2 is provided with an outer perforated cylinder 26 which is supported at one end on a hub 28 of a gear 29 keyed to a short shaft 30 journaled in suitable bearings 15! in the frame of the machine. The shaft 30 is arranged to be rotated through the gearing l8, previously described, The other end of the cylinder 26 is supported on a flange member 32 which is provided with a roller hearing 34 mounted upon an inwardly extended portion 36 of a suction pipe 38 supported in the frame of the machine. An end cap 39 is secured to the flange 32 to retain the roller 34 in operative position. The perforations 40 in the outer cylinder 26 preferably take the form of relatively closely spaced elongated radial slots which extend longitudinally of the cylinder. The cylinder is secured at each end to the flange members 32 and 28 by screws 42 and the intermeshing gears 29 effect rotation of the cylinders in opposite directions.

The suction pipe, as herein shown, is provided with a flanged portion 44 which engages one face of a side frame of the machine and is secured to the frame by a nut 4-6 cooperating with a threaded portion of the pipe and bearing against the opposite face of the frame. The outwardly extended portion of the suction pipe may be connected by a flexible tube 48 to any usual or preferred form of suction creating apparatus, not shown.

The adjustable sleeves 54, 56 which are arranged to confine the effect of the suction upon the outer laminae of the mica blocks at selected portions of the circumferenc of the perforated rollers l0, ['2 are herein shown as comprising an intermediate sleeve fitted within the outer cylinder and which is adjustably secured at one end to a stationary flange 58 supported upon the pipe extension 36 and at its other end to a flange member 60 which is provided with a roller bearing 62 in which the inner end of the short shaft 30 is rotatably mounted. The intermediate sleeve 54 is adjustably secured to the flanges 58, t0 by screws 64, and in practice each flange 58 659 may be provided with a plurality of tapped holes whereby adjustment may be effected by removing the screws from one set of tapped holes and after adjusting the sleeve 54 to a new position again introducing the screws 6 3 into the tapped holes provided at the new location, The flange 58 is retained in position on the stationary pipe 38 by a nut 50 cooperating with a threaded portion of the pipe and an end thrust washer 4l| may be provided between the flanges 32 and 58. The inner sleeve 53 may and preferably will be fitted snugly within the intermediate sleeve and may be provided with elongated circumferential slots to permit rotary adjustment of the same with respect to the intermediate sleeve 54 to thus provide the desired suction area adjacent the bight of the rollers. In the illustrated embodiment of the invention each sleeve extends 240 about the circumference of its roller leaving 120 open, so that a maximum open area of 120 is obtainable. As indicated in Fig. 2, one position of adjustment which has been found successful in the present apparatus comprises a setting of the intermediate sleeve 54 to present one edge substantially 10 above a horizontal line passing through the center of the rollers and the inner sleeve 50 disposed with one edge substantially 30 below said center line. In order to prevent mica flakes from entering the suction rollers, a relatively fine mesh 4 screen 19 in the form of a sleeve may and. preferably will be provided about the outer surface of the rollers, as illustrated.

Provision is also made in the illustrated embodiment of the apparatus for yieldingly mounting one of the suction rollers to permit mica blocks of various sizes to pass therebetween. As herein shown, the roller l2 may be supported between arms 12 which are pivotally mounted upon a cross rod 14 extended between the side frames of the machine, A spring connected to the arm 12 and to a portion of the machine frame is arranged to rock the roller l2 toward the fixed roller l0 and a stop stud 18 secured to the machine frame is arranged to engage the arms 12 to limit the rocking movement of the rollers toward each other to prevent actual engagement of the surfaces thereof with each other.

Provision is further made for sorting the mica flakes whereby the outer thin flakes 22 separated from the block of mica 20 are guided into compartments 80 disposed beneath each rol1er, the thicker flakes 24 being permitted to drop into an intermediate compartment 82 to be again introduced into the machine for further separating action. As herein shown, suitable adjustable guides may be provided for this purpose which include vertical guides 84 provided with extensions 86 secured to the side frames and arranged to provide lateral adjustment with respect to the rollers l0, l2 and vertical guides 88 secured to and cooperating with the upper ends of the guides 84 and arranged to be adjusted vertically with respect to the rollers to thus assure proper disposition of the guides for most eflicient sorting. Suitable guides 90 supported by the frame may be provided at the lower end of the apparatus to cooperate with depending extensions 94 of the laterally adjustable guides 84. Suitable guards 96 supported by the frame may also be provided adjacent the sides of the rollers as shown.

From the above description it will be observed that in the operation of the machine, the mica blocks to be split may be introduced into a hopper es to guide the blocks between the suction rollers l0, l2. Upon passing between the rollers, the effect of the suction, confined to the area adjacent the bight of the rollers, causes separation of the outer laminae from the block, permitting the outer layers or thin laminae to follow the contours of the rollers and to drop off into the comp-artments 80 provided therefor. The remaining intermediate piece of mica is engaged by the knife blade 26 to effect further separation of the laminae, the thinner flakes being caused to follow the contour of the rollers and to be dropped into compartments 80 and the thicker pieces dropping into the central compartment 82 to be again introduced into the apparatus for further separating action.

While the preferred embodiment of the invention has been herein illustrated and described it will be understood that the invention may be embodied in other forms within the scope of the following claims.

Having thus described the invention, what is claimed is:

l. Mica splitting apparatus having, in combination, a pair of cooperating rotatable cylinders having a relatively large number of suction openings distributed substantially uniformly around the surface thereof, said cylinders having provision for connection with a source of suction, and being disposed horizontally and with their lateral surfaces in closely disposed relation, each cylinder having therein stationary valve means so disposed as to confine the suction action to a relatively small arc extending slightly above and below a plane through the axes of the cylinders.

2. Mica splitting apparatus having, in combination, a pair of cooperating rotatable cylinders having a relatively large number of suction openings distributed substantially uniformly around the surface thereof, said cylinders having provision for connection with a source of suction, and being disposed horizontally and with their lateral surfaces in closely disposed relation, each cylinder having therein stationary valve means so disposed as to confine the suction action to a relatively small are extending slightly above and below the line of contact, and means permitting adjustment of said valve means to vary the position of said suction arc.

3. Mica splitting apparatus having, in combination, a pair of cooperating rotatable cylinders having a relatively large number of suction openings distributed substantially uniformly around the surface thereof, said cylinders having provision for connection with a source of suction, and being disposed with their lateral surfaces in closely disposed relation, each cylinder having therein stationary valve means so disposed as to confine the suction action to a relatively small are extending slightly above and below a plane through the axes of the cylinders.

4. Mica splitting apparatus having, in combination, a pair of cooperating rotatable rollers having a relatively large number of suction openings distributed substantially uniformly around the surface thereof, said rollers having provision for connection with a source of suction, and being disposed with their lateral surfaces in closely disposed relation, each roller having therein stationary valve means so disposed as to confine the suction action to a relatively small are extending slightly above and below the bight of the rolls, said valve means comprising a pair of sleeves open on one side arranged in overlapping relation, the adjacent edges of said sleeves defining the suction are, and means permitting adjustment of said sleeves to vary the extent of said arc.

5. Mica splitting apparatus having, in combination, a pair of cooperating rotatable rollers having a relatively large number of suction openings distributed substantially uniformly around the surface thereof, said rollers having provision for connection with a source of suction, and being disposed with their lateral surfaces in closely disposed relation arranged to effect separation of the outer laminae of a block of mica as it passes therebetween, and a knife blade disposed to engage the end of the mica block as it emerges from between said cylinders arranged to assist in the separating action.

6. Mica splitting apparatus having, in combination, a pair of cooperating rotatable cylinders having a relatively large number of suction openings distributed substantially uniformly around the surface thereof, said cylinders having provision for connection with a source of suction, and being disposed horizontally and with their lateral surfaces in closely disposed relation, each cylinder having therein stationary valve means so disposed as to confine the suction action to a relatively small are extending slightly above and below a plane through the axes of the cylinders, and a knife blade disposed immediately below said plane to engage the end of a mica block as it emerges from between said cylinders.

7. Mica splitting apparatus having, in combination, a pair of cooperating rotatable cylinders having a relatively large number of suction openings distributed substantially uniformly around the surface thereof, said cylinders having provision for connection with a source of suction, and being disposed horizontally and with their lateral surfaces in closely disposed relation, each cylinder having therein stationary valve means so disposed as to confine the suction action to a relatively small are extending slightly above and below a plane through the axes of the cylinders whereby to effect separation of the outer laminae of a block of mica as it passes therebetween, and adjustable guides defining sorting chambers arranged to sort the separated mica flakes and the remaining unsplit portions of the block.

8. Mica splitting apparatus having, in combination, a pair of cooperating rotatable cylinders having a relatively large number of suction openings distributed substantially uniformly around the surface thereof, said cylinders having provision for connection with a source of suction, and being disposed horizontally and with their lateral surfaces in closely disposed relation arranged to effect separation of the outer laminae of a block of mica as it passes therebetween, a knife blade disposed to engage the end of the mica block as it emerges from said cylinders for assisting in the separating action, and adjustable guides defining sorting chambers arranged to sort the separated mica flakes and the remaining unsplit portion of the block.

9. Mica splitting apparatus having, in combination, a pair of cooperating rotatable cylinders having a relatively large number of suction openings distributed substantially uniformly around the surface thereof, said cylinders having provision for connection with a source of suction, and being disposed horizontally and with their lateral surfaces in closely disposed relation, each cylinder having therein stationary valve means so disposed as to confine the suction action to a relatively small are extending slightly above and below the line of contact, one of said cylinders being yieldingly mounted with relation to its cooperating cylinder whereby to permit mica blocks of varying thickness to pass therebetween.

10. Mica splitting apparatus, in combination, a pair of cooperating rotatable cylinders having a relatively large number of suction openings distributed substantially uniformly around the surface thereof, said cylinders having provision for connection with a source of suction, and being disposed horizontally and with their lateral surfaces in closely disposed relation arranged to effect separation of the outer laminae of a block of mica as it passes therebetween, and a knife blade disposed to engage the end of the mica block as it emerges from said cylinders, said knife serving to enter between the laminae of and to deflect the unsplit block of mica against one of the suction cylinders thus assisting in the further separation of a second thin lamination.

CLARK GOODMAN.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 1,772,082 Frederick July 23, 1929 1,879,164 French Sept. 27, 1932 1,913,875 Frederick June 13, 1933 1,913,876 Frederick June 13, 1933 

